1. Field of the Invention
The present invention relates to a charge transfer device having a shift register.
2. Background of the Invention
There have been proposed so far various apparatuses using the image pickup function and analog memory function possessed by charge transfer devices. For example, in U.S. Pat. No. 4,263,623, an apparatus is proposed in which a charge transfer device is used as an image pickup device and a horizontal shift register provided with a charge injecting section is used as a memory.
Such an apparatus has a drawback in that if the signal to be input to the horizontal shift register does not have good linearity, the S/N ratio will deteriorate when the signal circulates many times in a circuit. In addition, although a delay line or the like using a CCD is known generally, a large problem on linearity of the input signal also occurs similarly. This is because, in conventional CCDs, when the input signal is input into the CCD with a predetermined periodic timing, unnecessary charges would have been mixed in the CCD even in the non-input timing.